Originally Posted by Michael Reuben

Originally Posted by Paul Hillenbrand:
What is known about dial-norm and DD TrueHD:

From another post:

Author and link, please. On this particular topic (DD and dialnorm), there has been a great deal of misinformation masquerading as expertise.

M.

Originally Posted by DaViD Boulet

....Roger Dressler has confirmed what I've said is accurate in several discussions at AVS.

DN flag (set to anything other than -31) causes the digital filter in the DD decoding engine to then recalculate the audio data (which *is* bit-for-bit accurate from TrueHD to start with) to perform digital-level-reduction based on the value. You no longer have bit-for-bit accuracy to the original data, just like running your audio data through a sampling rate converter or noise-shaping filter would re-write data.

This how it works. Even Dolby doesn't challenge this. The only thing Roger Dressler had to say was that he felt personally that the re-writing of the data didn't cause any serious sonic degredation to the signal (a natural point of view for him to take). But he confirmed 100% that the process I've described above is exactly how DN is applied.